Ejemplo n.º 1
0
        /// <summary>
        /// Predict a target using a linear binary classification model trained with the SDCA trainer, and a custom loss.
        /// Note that because we cannot be sure that all loss functions will produce naturally calibrated outputs, setting
        /// a custom loss function will not produce a calibrated probability column.
        /// </summary>
        /// <param name="catalog">The binary classification catalog trainer object.</param>
        /// <param name="label">The label, or dependent variable.</param>
        /// <param name="features">The features, or independent variables.</param>
        /// <param name="loss">The custom loss.</param>
        /// <param name="weights">The optional example weights.</param>
        /// <param name="options">Advanced arguments to the algorithm.</param>
        /// <param name="onFit">A delegate that is called every time the
        /// <see cref="Estimator{TInShape, TOutShape, TTransformer}.Fit(DataView{TInShape})"/> method is called on the
        /// <see cref="Estimator{TInShape, TOutShape, TTransformer}"/> instance created out of this. This delegate will receive
        /// the linear model that was trained, as well as the calibrator on top of that model. Note that this action cannot change the
        /// result in any way; it is only a way for the caller to be informed about what was learnt.</param>
        /// <returns>The set of output columns including in order the predicted binary classification score (which will range
        /// from negative to positive infinity), and the predicted label.</returns>
        public static (Scalar <float> score, Scalar <bool> predictedLabel) SdcaNonCalibrated(
            this BinaryClassificationCatalog.BinaryClassificationTrainers catalog,
            Scalar <bool> label, Vector <float> features, Scalar <float> weights,
            ISupportSdcaClassificationLoss loss,
            SdcaNonCalibratedBinaryClassificationTrainer.Options options,
            Action <LinearBinaryModelParameters> onFit = null)
        {
            Contracts.CheckValue(label, nameof(label));
            Contracts.CheckValue(features, nameof(features));
            Contracts.CheckValueOrNull(weights);
            Contracts.CheckValueOrNull(options);
            Contracts.CheckValueOrNull(onFit);

            var rec = new TrainerEstimatorReconciler.BinaryClassifierNoCalibration(
                (env, labelName, featuresName, weightsName) =>
            {
                options.FeatureColumnName = featuresName;
                options.LabelColumnName   = labelName;

                var trainer = new SdcaNonCalibratedBinaryClassificationTrainer(env, options);
                if (onFit != null)
                {
                    return(trainer.WithOnFitDelegate(trans =>
                    {
                        onFit(trans.Model);
                    }));
                }
                return(trainer);
            }, label, features, weights);

            return(rec.Output);
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Predict a target using a linear binary classification model trained with the SDCA trainer, and a custom loss.
        /// Note that because we cannot be sure that all loss functions will produce naturally calibrated outputs, setting
        /// a custom loss function will not produce a calibrated probability column.
        /// </summary>
        /// <param name="catalog">The binary classification catalog trainer object.</param>
        /// <param name="label">The label, or dependent variable.</param>
        /// <param name="features">The features, or independent variables.</param>
        /// <param name="loss">The custom loss.</param>
        /// <param name="weights">The optional example weights.</param>
        /// <param name="l2Regularization">The L2 regularization hyperparameter.</param>
        /// <param name="l1Threshold">The L1 regularization hyperparameter. Higher values will tend to lead to more sparse model.</param>
        /// <param name="numberOfIterations">The maximum number of passes to perform over the data.</param>
        /// <param name="onFit">A delegate that is called every time the
        /// <see cref="Estimator{TInShape, TOutShape, TTransformer}.Fit(DataView{TInShape})"/> method is called on the
        /// <see cref="Estimator{TInShape, TOutShape, TTransformer}"/> instance created out of this. This delegate will receive
        /// the linear model that was trained, as well as the calibrator on top of that model. Note that this action cannot change the
        /// result in any way; it is only a way for the caller to be informed about what was learnt.</param>
        /// <returns>The set of output columns including in order the predicted binary classification score (which will range
        /// from negative to positive infinity), and the predicted label.</returns>
        public static (Scalar <float> score, Scalar <bool> predictedLabel) SdcaNonCalibrated(
            this BinaryClassificationCatalog.BinaryClassificationTrainers catalog,
            Scalar <bool> label, Vector <float> features,
            ISupportSdcaClassificationLoss loss,
            Scalar <float> weights = null,
            float?l2Regularization = null,
            float?l1Threshold      = null,
            int?numberOfIterations = null,
            Action <LinearBinaryModelParameters> onFit = null)
        {
            Contracts.CheckValue(label, nameof(label));
            Contracts.CheckValue(features, nameof(features));
            Contracts.CheckValue(loss, nameof(loss));
            Contracts.CheckValueOrNull(weights);
            Contracts.CheckParam(!(l2Regularization < 0), nameof(l2Regularization), "Must not be negative, if specified.");
            Contracts.CheckParam(!(l1Threshold < 0), nameof(l1Threshold), "Must not be negative, if specified.");
            Contracts.CheckParam(!(numberOfIterations < 1), nameof(numberOfIterations), "Must be positive if specified");
            Contracts.CheckValueOrNull(onFit);

            var rec = new TrainerEstimatorReconciler.BinaryClassifierNoCalibration(
                (env, labelName, featuresName, weightsName) =>
            {
                var trainer = new SdcaNonCalibratedBinaryClassificationTrainer(env, labelName, featuresName, weightsName, loss, l2Regularization, l1Threshold, numberOfIterations);
                if (onFit != null)
                {
                    return(trainer.WithOnFitDelegate(trans =>
                    {
                        onFit(trans.Model);
                    }));
                }
                return(trainer);
            }, label, features, weights);

            return(rec.Output);
        }